Expulsion fuse



July 28, 1931. A. G. STEINMAYER 1,815,958

EXPULSION FUSE Filed July 22, 1929 v/v Effi/ /6 j fl` I i gg l/J Y "L Patented July 28, 1931 UNITED STATES PATENT OFFICE ALWIN G. STEINMAYER, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO LINE MATERIAL COMPANY, OF SOUTH MILWAUKEE, WISCONSIN, A CORPORATION OF DELAWARE EXPULSION FUSE Application med July 22, 1929.

This invention relates to certain new and useful improvements in expulsion fuses and has as one of its objects the provision of a fuse structure in which all live parts thereof are conned within the enclosing box or housing to prevent accidental contact therewith on the part of the operator, and at the same time insure the thorough venting of the gases, occurring upon volatilization of the fuse, outside of the box.

Another object of this invention resides in the provision of an extension member secured to the discharge end of the fuse structure and having an opening through which one end of the fuse element passes to be connected with the lower fuse contact and which serves to conduct gases generated upon rupture of the fuse exteriorly of the housing.

And a further object of this invention resides in the provision of an abrupt increase in the passage formed by the combined internal diameters of the fuse tube and the extension member and through which the gases generated upon rupture of the fuse element are expelled, and the positioning of the opening in the extension through which the fuse element passes directly outward of said increase in the passage, which places the opening out of the path of the expelled gases and prevents their discharge through the opening into the housing interior.

With the above and other objects in view which will appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, I have illustrated two complete examples of the physical embodiment of my invention constructed according to the best modes I have so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view partly in section and partly in side elevation of an expulsion fuse unit embodying my invention; and

Serial No. 379,929.

Figure 2 is a fragmentary view partly in section and partly in side elevation 0f the lower end of the fuse tube illustrating a modified form of my invention.

Referring now more particularly to the accompanying drawings, the numeral 5 designates a box or housing preferably' formed l of porcelain or other material having insulating qualities and which is of substantial rectangular shape having its open front face closed by a door 6 also of insulating material. The door 6 is attached, as at 7, to a hinge member 8 fixed by mounting bolts or other means 9, to the bottom 10 of the housing, and covers an opening 11 in the bottom 10, leading from the interior fuse compartment 12 of the housing. The door 6 is of a size and shape to conform with the open frontof the housing and when closed rests against a flange or vbead 18 formed therein as illustrated in Figure 1 to provide a substantially tight closure.

The rear wall 14 of the housing is preferably provided with an external enlargement 15 to which a mounting bracket 16 is secured,

and the side walls 17 of the housing are provided with apertures, not shown, registering with line terminal members 18 suitably mounted within the interior' of the housing as at 19 and in electrical engagement with spring contact clips 2O between which the fuse member proper, indicated generally as at 21, is adapted to be received to electrically bridge the lines, not shown, connected with the terminal members 18.

The fuse member proper consists of an elongated tube 22 of insulating material having upper and lower contact members 23 and 24 mounted at the upper end of the tube and at a point spaced from its lower end, respeci tively. A fuse element 25 passed through the tube 22 and electrically bridges the contact members by having its upper end electrically connected with the Contact member 23 and its lower end portion passed outwardly of the tube and up along its part 26 extended beyond the contact member 24 to be electrically connected therewith in any suitable manner, or as illustrated in my copending l application, Serial No. 178,557.

LLL

As is customary in structures of this type, the contact members of the fuse are engaged with the spring clips 2O which are thus electrically bridged through the element 25, and in the present instance the lower end of the tube 22 terminates .at apoint spaced inwardly from the bottom wall l() of the liousinj.: thus positioning the extended end portion of the Jfuse element entirely within the housing and protecting the operator against acci- 4secured tothe .eXtremelon-'er end of the tube 22 to vextend through ,the opening ll to a Ipo intexteriorly ofthe housing, the tube hav- ,ing' an opening QSjuntaposethe extreme lowerendof the tube 22 through which the fuse element 25 passes to be connected with the Vcontact.member Q4. rllhe sleeve or extension 27 inthe present instance has a bore ot less diameter than the lexternal diameter of the ,lowerend portion QG-o'f-thetube and its upper end iscounter-board to .a diameter vto 'eceive the lower end of the tube, the shoulder 29 at 'the 4bottomolt `the counter-bore limiting ythe 'facilitates the securement of the sleeve to the lower end oit the tube extension 26 after the .fuse element has been secured withirrthe tube.

From the foregoing description, taken in connection with the accompanying',drawings, `it will `be readily apparent `to those skilled in the art to ,whichan invention orn thercharacter described appertains,that `all live parts of the structure are entirely confined within and protectedby the housing or boxfand 4at the saine time the `n'ases occurring' upon volatilination of thetuse element .are thoroughly ventedv exteriorly off .the boit.

ft lwill also be noted vthat the opening 28 through which'the `fuse lelement is passed is ,positioned directly outward ot the end of the `tube26 and as the extensionineinberQT has lai'ger'internal diameter than the tube, the

opening' is out of. the path ofthe expelled gases whosevelocity, being` high, prevents a Ydiversion of the gases through the opening into the interior ofthe housing.

'The largenexternal. diameter of the eXten- `end or" the tube and providing' a continuation thereof, said extension member having an opening therein .pixtapose the lower end of fthe tube Ithrough which the fuse element ythanthe,tube and 'rigidly secured to its lower endio 'form acontinuation thereof,.and said ension member having;` an opening therein apose the lower end ot the tubeithrough Iwhich the .fuse element passes.

8. In a fuse constructiomthe combination ywith a housing` member having` a front open tace andareeessed bottom wall, a closure 'tor the open face ot `the housing' member and switch terminal members secured within the housing' interioi'in alignment with the opening in the bottom wall, Yof .a `fuse member adapted to be mounted within the housingr member by the switch teriniual members to lelectrically.bridgethe same and 4including` an insulating` tube, a pair of terminal engaging` contact members, -means mounting one terminal. engagingcontact member on the upper end portion of the tube, .means mounting the other terminal engaging contact member on the tube inwardlyiof its,lowei'.end,,a fuseele- Vment having' one end electrically connected with the upper terminal engaging contact l" member Vand beingpassed through the tube outwardly of its `lower end and up along' the exterior thereof, means electrically connectinn' ythe lfuse element with the lowei' terminal engaging' Contact member, the lowerlend of. I

the tube andthe fuse/,element carried thereby being infline with tlieopening' in the housing,T member bottom wall rbut spaced inwardly theretromtoprevent accidental contact therewith trom the housing` member exterior, and

an open ,ended extension member Vcarried by the tube and extending through `the opening in the housingrmember bottom wall, the ,fbore of said eiztensionmemher forming a continuation ot the tube bore and the Vfuse element ll t) passing through an opening in the wall of the extension member' inwardly of the bottom wall of the housing member.

4f. In a device of the character described, a normally closed housing having an opening in one wall, a fuse tube mounted within the housing with one end communicated with the exterior oi' the housing through said opening, contact members on the tube, terminal members mounted within the housing and adapted to receive the contact members, and a fuse element within the tube having one end electrically connected with one contact member and its other end passed outwardly of the tube at a pointl inside the wall having the opening and directed along its exterior to be electrically connected with the other contact member, whereby said fuse element is entirely within the housing to prevent accidental contact therewith from the housing exterior.

5. In a device of the character described, the combination with a normally closed housing having line terminals therein, of a fuse electrically bridging 'the terminals and comprising a tube, contact members engageable with the line terminals, a fuse element within the tube having one end connected with one Contact member and its other end passed outwardly of one end of the tube and connected with the other contact member exteriorly ot the tube, and a bored extension member carried by said end of the tube and projected through an opening in one wall of the housing at all times communicating the tube interior with the exterior of the housing and having an opening adjacent the end of the tube through which the fuse element'passes, the diameter of the extension member bore being greater than that of the tube to provide an abrupt enlargement of the passage formed by the tube and extension member through which gases generated upon volatization of the fuse element are expelled, said enlargement being positioned adjacent the opening through which the 'fuse element passes to prevent gases passing through the opening and into the housing interior.

6. A` fuse of the character described, comprising a tubular enclosing member having its internal diameter abruptly increased adjacent its discharge end and having an opening in its wall communicating' with its portion of increased internal diameter, contacts associated with the enclosing member, and a fuse element having one end connected with one contact member and its other end passed outwardly through said opening of the enclosing member and directed along the outside of the enclosing member to be connected with the olher contact, whereby the Velocity and path of gases expelled upon volatization of the fuse at the time they pass the opening l through which the fuse element passes is such as to preclude discharge of gases through said opening.

7. In a device of the character described, the combination with a housing having spaced line terminals therein, of a fuse electrically bridging the line terminals and comprising a tube, contacts engageable with the line terminals, a fuse element having one end connected with one contact and its other end passed outwardly of one end of the tube and bent back along its exterior to be connected with the other contact, the tube being of such length that it and the fuse element are entirely confined within the housing, and a bored member extended from the tube and having an opening through which the fuse element passes and projecting through an opening in one wall of the housing to conduct gases generated upon rupture of the fuse exteriorly of the housing, the diameter of the member bore being larger than that of the tube to provide an abrupt increase in the size of the passage through which the gases are expelled directly adjacent th-e opening through which the fuse element passes which prevents gases from being discharged through said opening into the interior of the housing.

S. In a device of the character described, the combination of the housing having spaced line terminals therein, of a fuse bridging the terminals and comprising a tubular enclosing member having` its internal diameter abruptly increased adjacent its discharge end, contacts engageable with the line terminals, and a fuse element having one end connected with one contact and its other end passed outwardly through an aperture in the portion of the enclosing member having the increased internal diameter and extended along the exterior of the enclosing member to be connected with the other contact, the aperture in the enclosing' member being disposed within the housing whereby all live parts are conlined within the housing and that portion orn the enclosing member having an increased internal diameter projecting through an opening in said wall of the housing to conduct gases generated upon rupture of the :t'use exteriorly of the housing, said aperture being located out of the path of expelled gases precluding their discharge through the aperture into the housing interior.

In testimony whereotI I have hereunto affixed my signature.

ALWIN G. STEINMAYER. 

